Disable unused extruders (motors)

Paxy

With diamond color mixing setup there is 3 extruders (extuder motors).

If I print with only one extruder (mostly first one) other should be disabled.

Right now (0.92.2) two unused extruders are also enabled and get heated even if print do not have job for them.

Probably, best solution is that Disable heater timeout should be counted for every exturder separatly not together.

Repetier

We only have one timeout for ALL motors including xyz. And enable enables all motors defined for your extruder. While I see that it would make sense in your special case, I'm not sure it is in general a good idea. Especially if you switch between mixing/not mixing disabling single motors might shift extruder motor position with unprecise starting condition when enabled. Plus it adds a very complex strategy I can not even test (have no mixing extruder printer) so the risk is too high to test it. Motors should be able to handle the heat anyway. Think of z motor for example.

Repetier

One more reason not to do so from an other thread:

"In my experiments with a dual extruder with one nozzle last night it became clear to me that you cannot allow one stepper to be shut down while you use the other. When this is the case, the pressure from the driven extruder forces material into the non-operating side of the block and that requires an undesirable amount of flow from the other extruder before you start seeing the second color after you enable it."

rhklein

Repetier wrote
One more reason not to do so from an other thread:
"In my experiments with a dual extruder with one nozzle last night it became clear to me that you cannot allow one stepper to be shut down while you use the other. When this is the case, the pressure from the driven extruder forces material into the non-operating side of the block and that requires an undesirable amount of flow from the other extruder before you start seeing the second color after you enable it."

This is definitely true for the diamond hotend.
I wonder if extruders are effected by STEPPER_INACTIVE_TIME?
If I print with 1 extruders out of 3 for longer then the inactive_time, do they get disabled?

Repetier

STEPPER_INACTIVE_TIME means no motor is used for that time and then all get disabled. This will never happen during a print as you always have some parts moving. Only time you would be able to get that is during a pause longer then STEPPER_INACTIVE_TIME.